Thickened aqueous detonator composition containing a brisant explosive



United States Patent Ofiice 3,369,944 Patented Feb. 20, 1968 3,369,944THICKENED AQUEOUS DETONATOR COMPOSI- TION CONTAINING A BRISANT EXPLOSIVEAdolf Berthmann, Leverkusen, and Paul Lingens, Co-

logne-Maricnburg, Germany, and Clemens Franze, deceased, late ofLeverkusen, Germany, by Anneliese Franze, heiress, Leverkusen, Germany,assignors to Dynamit Nobel Aktiengesellschaft Patentabteilung,Troisdorf, Bezirk Cologne, Germany, a corporation of Germany No Drawing.Filed June 8, 1964, Ser. No. 374,229 Claims priority, applicationGermany, June 12, 1963, D 41,752 8 Claims. (Cl. 14939) This inventionrelates to detonation charges for blasting explosives, and moreparticularly this invention relates to detonation charges for blastingexplosives that are relatively non-sensitive in handling andnon-hazardous during the manufacture and packing of the same intocartridges or the like, but which can readily be brought to detonationand which are prepared from mixtures of at least one brisant explosivewith water or another aqueous solution.

Explosive compositions, such as mixtures of ammonium nitrate,trinitrotoluene and water, mixtures of ammonium nitrate and diesel oil,and cast charges of TNT, for which brisant detonating charges (primers)are required to initiate the detonation instead of blasting caps orinstantaneous fuses, are already known. Cast or pressed bodies of solidbrisant explosives, such as cast charges of TNT and Hexogen(cyclotrimethylenetrinitroamine), pressed bodies of desensitized PETN(pentaerythritol tetranitrate) or tetryl (tetranitromethylaniline), etc.or of nitric acid esters and ammonium nitrate are usually used as thedetonators.

The conventional detonating charges, however, are extremely sensitive toshock and impact. For example, when drilling into charges that have notbeen completely detonated in blast holes, there is the ever presentdanger of producing detonation. In long bore holes having relativelysmall cross-sections, solid, rigid detonating charges are difficult toinsert because of the possibility of canting. Gelatinized blastingexplosives cannot reliably be brought to their maximum speed ofdetonation by establishing contact therewith with an instantaneous fuse,but are usually brought only to their lowest speed of detonation, whichis not always sufiicient for the initiation of the explosive charge.

It is one of the objects of the present invention to teach a practicalutilization of charges of mixtures of brisant explosives with water oranother aqueous solution in initiating detonation in bore hole blasting.

It is another object to teach efficient detonating compositions for usein bore hole blasting, wherein charges of mixtures of brisant explosiveswith water or another aqueous solution, accomplish detonation resultsbeyond the expectations of conventional blasting.

It is still another object to teach efiicient detonation compositionsfor use in bore hole blasting, wherein explosive handling is greatlysimplified and blasting effectiveness is vastly increased.

Further objects and advantages will become apparent to those skilled inthe art as the description proceeds.

'In accordance with the invention it has now surprisingly been foundthat mixtures of brisant explosives with water or an aqueous solution,such as have been described in the literature (M. A. Cook, Science ofHigh Explosives, Reinhold PublishingCorp 1958, pp. 316 et seq), can beused as detonating charges. The detonating charges are required to be ofa composition that is determined empirically, so that they can bebrought reliably to a sufficiently high speed of detonation (e.g.,greater than 5000 m./sec.) by means of an instantaneous fuse applied tothem.

Brisant explosives, which are practically insoluble in water, and whichhave been found particularly suitable for the manufacture of thedetonating charges of the present invention include compounds such assolid nitric acid esters, e.g., pentaerythritol tetranitrate, nitromannitol, nitro starch, nitrated aromatic compounds, e.g.tn'nitrotoluene, and nitramines, e.g., cyclotrimethylene trinitramine,cyclotetramethylene tetranitramine, trinitrophenyl-methylnitramine andthe like. Mixtures of the above mentioned brisant explosives can also beused to great advantage. The lower limit of the brisant component of thedetonator charge amounts to approximately 50 percent by weight. Thislimit is determined substantially by the particular speed of detonationrequired (above 5000 rn./sec.). The brisant explosives are used inamounts varying from 50 to 85% of weight, and preferably from 60 to ofweight.

In place of water, aqueous solution can also be used in accordance withthe invention, which contain in addition to salts (salts whichparticipate in the detonation, such as alkali and alkaline earth metalnitrates and perchlorates, or inert salts of the type alkaline earthmetal chlorides), swelling agents. The water content or the content ofthe aqueous solution in the detonating charge should advantageouslyamount to not less than 5 percent by weight at the very least. An amountof water varying from 15 to 30% of weight, and preferably from 20 to 30%of weight is generally applied, when water is used without addition ofsalts. In the case of aqueous solution of salts the amount of water isvarying from 5 to 20% of weight, and preferably from 5 to 12% of weight.While amounts of salts varying from 10 to 45% of weight, and preferablyfrom 15 to 30% of weight are used.

Swelling agents applied in accordance with the present invention mayinclude compounds of the group consisting of guar flour, alginates,agar-agar, cellulose, carboxymethylcellulose and the like. Theseswelling agents are added in amounts varying from 0.1 to 5% of weight,and preferably from 0.1 to 2% of weight.

Powdered metals can also be added to the new detonating charges.Prepared aluminum and magnesium powders and powdered alloys thereof haveproven to be particularly advantageous in this regard. The amounts ofpowdered metals may vary from 1 to 35% of weight. The range preferredvaries from 5 to 20% of weight.

The novel detonating charges can be used for initiating the detonationof high explosives in the same quantities as have conventionally beenused hitherto in the explosive industry for other detonating charges.The detonator is most advantageously used in cartridge form. One notinconsiderable advantage of the detonators in accordance with theinvention is that they can be brought in fairly large quantities to thesite of the explosion and can there be loaded in the quantity requiredfor the explosion. Thus, at that point they can be loaded into metal,plastic, or like canisters, and be used in that form. They can also becartridged in tubes, bags or other such containers, constructed ofplastic or waterproof paper of the type conventionally used in theexplosive art.

The use of the detonator charges of the present invention has stillfurther advantages over those charges presently usedln comparison withpressed or cast charges of solid, high explosives, and in comparisonwith gelatinous explosives prepared on the basis of nitric acid esters,safety in handling is considerably improved. While pentolite (mixturesof trinitrotoluene and pentaerythritol tetranitrate) and ammoniumgelites can be brought to detonation six times out of six, using a drophammer having a hammer weight of 1 kg. and a drop height of 50 cm.,

the detonating charge as described in Example 1 (infra) requires kg. ofhammer weight for the same drop height under substantially identicalconditions. Furthermore, due to their water content, the detonationcharges of the invention are characterized by a reduced infiammability.In spite of their greater handling safety, the new detonating charges ofthe invention are brought, without any difficulty, to a high speed ofdetonation by an attached instantaneous fuse.

Further, due to their plasticity, the detonation charges of theinvention can be applied wherever and whenever the use of rigidexplosive bodies encounters difliculties or is contra-indicated.

The invention will be further illustrated by detailed description inconnection with the following specific examples of the practice of it.

EXAMPLE 1 Composition:

70 wt. percent pentolite (50/50), grain size 1 30 wt. percent thickenedsolution of:

10.4 parts Ca(NO 11.9 parts NH NO 7.5 parts H O, 0.2 part guar flour.

Explosive characteristics: Density: 1.52 g./cc. Trauzl lead blockexpansion:

325 cc. Speed of detonation:

6600 to 6800 m./sec.

The high speed of detonation was achieved, most surprisingly, eventhough initiation of the explosive charge column was brought about by aPETN fuse from a distance of half a centimeter, the explosive havingbeen contained in a plastic tube having a wall thickness of 0.15

Use.The above-described explosive was used successfully as a detonatingcharge for mixtures of ammonium nitrate, TNT and water in largebore-hole blasting in massive basalt. The detonating charge wascontained in a cartridge constructed of flexible plastic tubing andhaving a length of 200 mm. and a diameter of 50 mm. which easilyinserted into the bore hole because of its flexibility. Explosionscarried out under the same conditions using a gelatinous rock blastingexplosive (Ammongelit described in Chemische Technologie' by Winnackerand Weingartner, Carl Hanser Verlag, Munich, 1960, vol. 4, pp. 754) asthe detonating charge resulted in a far lesser explosive eflt'ect.

EXAMPLE 2 Composition:

65 wt. percent pentolite (50/50), grain size 1 mm., 35 wt. percentthickened solution of:

12.2 parts Ca(NO 14 parts NH NO 8.6 parts H O, 0.2 part guar flour.

Explosive characteristics:

Density: 1.55 g./cc. Trauzl lead block expansion:

300 cc. Detonation speed:

6300 to 6400 m./sec.

Use. A mixture of 44% nitrocellulose powder (consisting of 85 wt.percent nitrocellulose and 15 wt. percent stabilizer and plasticizer inthe form of cord grains having 4.8 mm. diam. and a length of 11.8 mm.),24% NH NO 31.9% of a salt solution saturated with Ca(NO and NH NO and0.17 guar flour was prepared. 400 g. of the detonating mass as abovedescribed were placed in a cartridge made of flexible plastic tubing 4(50 mm. diam.) which in turn were placed in an iron pipe having a lengthof 700 mm., a diameter of 65 mm., and wall thickness of 4 mm., closed atone end, and were detonated with an instantaneous fuse applied to them.The entire iron pipe was fragmented. Under the same experimentalconditions, using, however, various rock blasting explosives(Ammongelit) as the detonating charge, the iron pipe was intact, andonly the piece in which the detonating charge 'was contained wasdestroyed. In the case of initiation by an attached instantaneous fuse,the detonating charges made of explosives based on nitric acid estersdetonated with a speed of 2 to 3 thousand meters per second, while thedetonating charge of pentolite and aqueous solution had a detonationspeed of 6300 m./sec.

EXAMPLE 3 Composition:

61 wt. percent pentolite (50/ 50), grain size 0.1

mm., 8.7 wt. percent aluminum, 30.3 wt. percent thickened solution of:

10.5 parts Ca(NO 12.0 parts NH NO 7.6 parts H O, 0.2 part guar flour.

Explosive characteristics:

Density:

1.60 g./ cc. Trauzl lead block expansion:

350 cc. Speed of detonation:

6500 to 6800 m./sec.

Use.-There was placed in an iron pipe (length 1 m., diam. 50 mm., wallthickness 4 mm.) a mixture of ammonium nitrate and diesel oil (94 partsand 6 parts), which could not be brought to detonation with a blastingcap, and 100 grams of the above-described detonating charge. Theinitiation was carried out with a No. 8 aluminum blasting cap. The ironpipe was fragmented over its entire length.

EXAMPLE 4 Composition:

76.5 wt. percent of a mixture of 60 parts hexogen and 40 parts TNT(grain size 1 mm.) 23.5 wt. percent of a thickened solution of:

8.1 parts Ca(NO 9.3 parts NH NO 5.9 parts H O, 0.2 part guar flour.

Explosive characteristics:

Density:

1.58 g./cc. Trauzl lead block expansion:

350 cc. Speed of detonation:

7 100 m. /sec.

Use.This detonating charge was used for the purpose of detonating aground nitrocellulose powder in cartridges made of flexible plastictubing of a length of 700 mm. and a diameter of 65 mm. placed in a blasthole having a length of 10 m. and an mm. diam. in passive limestone. Theresulting explosion was entirely successful. The debris after theexplosion was indesirable form.

EXAMPLES 5 TO 8 The effect of additional detonating charges, having alength of 50 mm. and a 30 mm. diam. was evaluated on cast TNT bodies(length 200 mm., diam.- 50 mm). In all cases, the TNT bodies werebrought'to detonation.

The compositions and explosive characteristics of the detonating chargesare given in the following table:

6 5.9 parts H O, 0.2 part guar flour.

TABLE Examples DETONA'IING CHARGES Composition (wt. percent):

Pentolite (grain size 0.1 mm.) 72. 3 61 PETN 70 0. I III: I: 0.

11. 9 7. 6 6. 4 17. 9 Guar flour 0. 2 0. 2 0. 2 0. 2 Explosivecharacteristics:

Density, g./ec 1. 32 1. 50 1. 64 1. 57 Trauzl lead block expansion in cc5 35 330 Detonation speed, rn./see.

EXAMPLE 9 Composition:

70 wt. percent pentolite (50/50), grain size 1 mm. 30 wt. percentthickened solution of:

parts NaClO 14 parts H 0, 1 part agaragar.

Explosive characteristics:

Density:

1.50 g./-cc. Trauzl lead block expansion:

330 cc. Speed of detonation:

6600 m./ sec.

Use.This detonating charge was used successfully in a test explosionaccording to Example 1.

We claim:

1. A detonator composition of reduced hazard during manufacture and ofsubstantially full sensitivity to detonation at the time of use, thecomposition consisting of:

70 Wt. percent pentolite (50/ 50), grain size 1 mm.,

wt. percent thickened solution of:

10.4 parts Ca(NO 11.9 parts NH NO 7.5 parts H O,

0.2 part guar flour.

2. A detonator composition of reduced hazard during manufacture and ofsubstantially full sensitivity to detonation at the time of use, thecomposition consisting of:

65 wt. percent pentolite (50/50), grain size 1 mm.,

Wt. percent thickened solution of:

12.2 parts Ca(NO 14 parts NH NO 8.6 parts H O,

0.2 part guar flour.

3. A detonator composition of reduced hazard during manufacture and ofsubstantially full sensitivity to detonation at the time of use, thecomposition consisting of:

61 wt. percent pentolite (/50), grain size 0.1 mm.,

8.7 Wt. percent aluminum,

30.3 wt. percent thickened solution of:

10.5 parts Ca(NO 12.0 parts NH NO 7.6 parts H O,

0.2 part guar flour.

4. A detonator composition of reduced hazard during manufacture and ofsubstantially full sensitivity to detonation at the time of use, thecomposition consisting of:

76.5 wt. percent of a mixture of parts hexogen and 40 parts TNT (grainsize 1 mm.),

23.5 wt. percent of a thickened solution of:

8.1 parts Ca(NO 9.3 parts NH NO 5. A detonator composition of reducedhazard during manufacture and of substantially full sensitivity todetonation at the time of use, the composition consisting of:

72.3 wt. percent of pentolite,

27.5 wt. percent of water, and

0.2 wt. percent guar flour.

6. A detonator composition of reduced hazard during manufacture and ofsubstantially full sensitivity to detonation at the time of use, thecomposition consisting of:

61 wt. percent of pentolite,

10.6 wt. percent of Ca(NO 7.6 wt. percent of water,

20.6 wt. percent of NH NO 0.2 wt. percent guar flour.

7. A detonator composition of reduced hazard during manufacture and ofsubstantially full sensitivity to detonation at the time of use, thecomposition consisting of:

74.3 wt. percent of cyclotrimethylenetrinitroamine,

8.9 wt. percent Ca(NO 10.2 wt. percent NH NO 6.4 wt. percent water,

0.2 wt. percent guar flour.

8. A detonator composition of reduced hazard during manufacture and ofsubstantially full sensitivity to detonation at the time of use, thecomposition consisting of:

70 wt. percent PETN,

11.9 wt. percent CaCl 17.9 wt. percent water,

0.2 Wt. percent guar flour.

References Cited UNITED STATES PATENTS Re. 26,115 11/1966 Schwoyer 149412,942,965 6/1960 Westheimer et a1 14939 2,982,641 5/1961 Dawson et a1.149-39 3,222,232 12/1965 Schwoyer 14938 3,062,143 11/1962 Savitt et a1.149-93 XR 3,096,223 7/1963 Cook et a1. 149-105 XR 3,155,038 11/1964Smith 14993 XR 3,299,811 1/1967 Gates 14992 XR 3,326,731 6/1967 Noddin14992 XR OTHER REFERENCES Mellor, J. W., Mellors Modern InorganicChemistry, Longmans, Green and Co, New York, 1951, QD5, M52, 04 (p.422).

CARL D. QUARFORTH, Primary Examiner.

BENJAMIN R. PADGETT, Examiner.

S. J. LECHERT, JR., Assistant Examiner.

3. A DETONATOR COMPOSITION OF REDUCED HAZARD DURING MANUFACTURE AND OFSUBSTANTIALLY FULL SENSITIVITY TO DETONATION AT THE TIME OF USE, THECOMPOSITION CONSISTING OF: 61 WT. PERCENT PENTOLITE (50/50), GRAIN SIZE<0.1 MM., 8.7 WT. PERCENT ALUMINUM, 30.3 WT. PERCENT THICKENED SOLUTIONOF: 10.5 PARTS CA(NO3)2, 12.0 PARTS NH4NO3, 7.6 PARTS H2O, 0.2 PART GUARFLOUR.
 4. A DETONATOR COMPOSITION OF REDUCED HAZARD DURING MANUFACTUREAND OF SUBSTANTIALLY FULL SENSITIVITY TO DETONATION AT THE TIME OF USE,THE COMPOSITION CONSISTING OF: 76.5 WT. PERCENT OF A MIXTURE OF 60 PARTSHEXOGEN AND 40 PARTS TNT (GRAIN SIZE <1MM.), 23.5 WT. PERCENT OF ATHICKENED SOLUTION OF: 8.1 PARTS CA(NO3)2, 9.3 PARTS NH4NO3, 5.9 PARTSH2O, 0.2 PART GUAR FLOUR.
 7. A DETONATOR COMPOSITION OF REDUCED HAZARDDURING MANUFACTURE AND OF SUBSTANTIALLY FULL SENSITIVITY TO DETONATIONAT THE TIME OF USE, THE COMPOSITION CONSISTING OF: 74.3 WT. PERCENT OFCYCLOTRIMETHYLENETRINITROAMINE, 8.9 WT. PERCENT CA(NO3)2, 10.2 WT.PERCENT NH4NO3, 6.4 WT. PERCENT WATER, 0.2 WT. PERCENT GUAR FLOUR.